We plan to continue our survey of the microbial flora of the surface of the skin of persons with acne and of those with little or no acne. During the past year considerable quantitative data on propionibacteria were obtained and studies concentrated on the face. We will carry out more studies on the back and will search for potentially significant differences in organisms other than propionibacteria in addition to extending the studies on that group of organisms . We will establish a data base for future studies of flora as acne diminishes in certain subjects.